A steam generator iron is used to remove creases from the fabric of a garment or other material. Such a steam generator iron comprises a head unit having a main body with a handle which is held by a user, and a sole plate with a planar surface which is pressed against the fabric of a garment. A water receiving chamber and a steam generating unit are disposed in the main body, so that water is fed from the water receiving chamber into the steam generating unit and converted into steam. The steam then flows along a steam passageway and is discharged from the steam generator iron through vent holes in the sole plate towards the fabric of a garment. The steam is used to heat up and momentarily moisten the fabric of the garment in an attempt to obtain effective removal of creases from the fabric.
Steam generator irons are generally optimised for a high steam output rate. However, such a high fluid flow velocity can produce high sound power levels due to flow instabilities, for example turbulence or vortices, as the fluid flows along the flow path. In particular, flow instabilities may be formed due to a transition of the flow from one section of a steam passageway to another section, a change in direction or an obstacle in the flow path. Moreover, it is known that some geometrical configurations of the flow path can lead to a loud whistling noise being generated due to vortices being generated in the fluid flow. Although it is possible to limit the generated noise levels by altering the geometrical configuration of the flow path, for example by increasing the cross-sectional area of the flow path, the extent of the reduction is limited.